Influence of drying temperature and maturity at harvest on biochemical properties and quality of jujube fruit

Jujube is one of the invaluable fruits from nutritional and medicinal aspects. However, its shelf life is short in ambient temperature. Drying is used as a common method to extend the shelf life, but optimum maturity stage at harvest and drying conditions is crucial for maximizing the nutritional value and maintaining the antioxidant properties during the processing stage. Hence, the effect of drying temperature and maturity stage (crisp mature and full ripe) on quality parameters, sensory and antioxidant properties of jujube fruit was examined. The results showed that the higher values of total phenolic content, ascorbic acid, and skin color characteristics include lightness (L*), redness (a*) and chroma (C*) were obtained in fruit harvested at crisp mature fruit. An increase in ascorbic acid, antioxidant activities and L*, a* and C* values were obtained in fruit dried at a lower temperature (45°C), while the greater value of hue (h°) was achieved at fruit dried at a higher temperature (60°C). In general, from sensorial and nutritional aspects, fruits harvested at fully ripe stage and dried at a lower temperature (45°C) were better.